Liposomal vaccine formulations as prophylactic agents: design considerations for modern vaccines

Influenza
Influenza is an infectious disease caused by the influ-
enza virus, affecting human health with a pandemic 
effect in several instances. The virus is divided in three 
types (A, B and C) and it is spread through the air from 
coughs and sneezes, therefore the importance for vac-
cine development studies for the infection. An intranasal 
(i.n.) liposomal influenza vaccine study was presented 
by Joseph et al. [
45
]. The vaccine formulation developed 
by the group was based in the polycationic sphingolipid 
N-palmitoyl-d-erythro-sphingosyl-carbamoyl-spermine 
(or ceramide carbamoyl-spermine, CCS) and was com-
pared with other formulations containing monocationinc 
phospholipids (DC-Chol, DDA, DSTAP (1,2-stearoyl-
3-trimethylammonium-propane), DMTAP and DOTAP). 
Cholesterol was added to increase liposome fluidity and 
the lipids DMPC and DMPG were included in neutral 
and anionic formulations, respectively. All formulations 
contained the influenza A antigens hemagglutinin and 
neuraminidase (HN). DMTAP- and DOTAP-based vac-
cines were the only monocationic lipid formulations 
to induce strong systemic (serum) and local (lung) T
H
1 
and T
H
2 responses. Surprisingly, DDA-containing for-
mulations did not induce strong, or significant, local or 
systemic immune responses. No specific reasons were 
provided by the team for such results but we can infer 
that vesicle morphology (multilamellar and oligolamel-
lar cationic formulations), size (1–4 µm diameter) and 
encapsulation efficiencies (10–90% for non-CCS cationic 
formulations) would be responsible. The CCS-based vac-
cine formulation was the only formulation to be at the 
same or superior level of effectiveness compared to the 
commercially available vaccine with cholera toxin as the 

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De Serrano and Burkhart  J Nanobiotechnol (2017) 15:83 
adjuvant. More recently, researchers investigated a tri-
ple co-culture model of the human respiratory tract to 
study the immunostimulatory responses of virosomes 
and liposomes and their internalization [
86
]. The epithe-
lial cell line 16HBE was grown with monocyte-derived 
macrophages (MDMs) and dendritic cells (MDDCs) 
and exposed to liposomes and virosomes to evaluate the 
immune responses elicited by the nanocarriers. The viro-
somes were liposomes prepared with solubilized influ-
enza A/Brisbane/59/2007 H1N1 membrane proteins 
and included the neutral lipids DOPC and OPPE (1-pal-
mitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine, 
POPE). Liposomes were prepared with previously men-
tioned neutral lipids and no influenza soluble membrane 
proteins were added. Virosomes were internalized more 
efficiently by all cell types in mono- and co-cultures, 
with APCs like MDMs and MDDCs presenting the high-
est internalization levels as per flow cytometry and laser 
scanning microscopy. MDDCs were moderately activated 
by liposomes and virosomes in monocultures, and induc-
ing elevated levels of cytokine (IL-1β and IL-8) produc-
tion in co-cultures. Virosomes were internalized at higher 
levels in epithelial cells in comparison to liposomes.